Active ingredient of cannabis has no effect on the progression of multiple sclerosis

June 15, 2012

The first large non-commercial study to investigate whether the main active constituent of cannabis (tetrahydrocannabinol or THC) is effective in slowing the course of progressive multiple sclerosis (MS) shows that there is no evidence to suggest this; although benefits were noted for those at the lower end of the disability scale.

The CUPID (Cannabinoid Use in Progressive Inflammatory brain Disease) study was carried out by researchers from the Peninsula College of Medicine and Dentistry (PCMD), Plymouth University. The study was funded by the Medical Research Council (MRC) and managed by the National Institute for Health Research (NIHR) on behalf of the MRC-NIHR partnership, the Multiple Sclerosis Society and the Multiple Sclerosis Trust.

The preliminary results of CUPID are to be presented by lead researcher Professor John Zajicek at the Association of British Neurologists' Annual Meeting in Brighton on Tuesday 29th May.

CUPID enrolled nearly 500 people with MS from 27 centres around the UK, and has taken eight years to complete. People with progressive MS were randomised to receive either THC capsules or identical placebo capsules for three years, and were carefully followed to see how their MS changed over this period. The two main outcomes of the trial were a disability scale administered by neurologists (the Expanded Disability Status Scale), and a patient report scale of the impact of MS on people with the condition (the Multiple Sclerosis Impact Scale 29).

Overall the study found no evidence to support an effect of THC on MS progression in either of the main outcomes. However, there was some evidence to suggest a beneficial effect in participants who were at the lower end of the disability scale at the time of enrolment but, as the benefit was only found in a small group of people rather than the whole population, further studies will be needed to assess the robustness of this finding. One of the other findings of the trial was that MS in the study population as a whole progressed slowly, more slowly than expected. This makes it more challenging to find a treatment effect when the aim of the treatment is that of slow progression.

As well as evaluating the potential neuroprotective effects and safety of THC over the long-term, one of the aims of the CUPID study was to improve the way that clinical trial research is done by exploring newer methods of measuring MS and using the latest statistical methods to make the most of every piece of information collected. This analysis will continue for several months. The CUPID study will therefore provide important information about conducting further large scale clinical trials in MS.

Professor John Zajicek, Professor of Clinical Neuroscience at PCMD, Plymouth University, said: "To put this study into context: current treatments for MS are limited, either being targeted at the immune system in the early stages of the disease or aimed at easing specific symptoms such as muscle spasms, fatigue or bladder problems. At present there is no treatment available to slow MS when it becomes progressive. Progression of MS is thought to be due to death of nerve cells, and researchers around the world are desperately searching for treatments that may be 'neuroprotective'. Laboratory experiments have suggested that certain cannabis derivatives may be neuroprotective."

He added: "Overall our research has not supported laboratory based findings and shown that, although there is a suggestion of benefit to those at the lower end of the disability scale when they joined CUPID, there is little evidence to suggest that THC has a long term impact on the slowing of progressive MS."

Dr Doug Brown, Head of Biomedical Research at the MS Society, said: "There are currently no treatments for people with progressive MS to slow or stop the worsening of disability. The MS Society is committed to supporting research in this area and this was an important study for us to fund. While this study sadly suggests THC is ineffective at slowing the course of progressive MS, we will not stop our search for effective treatments. We are encouraged by the possibility shown by this study that THC may have potential benefits for some people with MS and we welcome further investigation in this area."

Related Stories

(Medical Xpress) -- The first large non-commercial study to investigate whether the main active constituent of cannabis (tetrahydrocannabinol or THC) is effective in slowing the course of progressive multiple sclerosis (MS) ...

Researchers from Mount Sinai School of Medicine will present several key studies at the American Academy of Neurology (AAN) annual meeting, including research providing critical insight into the prognosis and clinical treatment ...

(Medical Xpress) -- Pregnancy appears to have a positive effect on long-term disability in women with two types of multiple sclerosis, indicating that reproductive hormones may play a protective role in MS progression, neurology ...

Recommended for you

Massachusetts General Hospital (MGH) researchers have developed what appears to be a significant improvement in the technology behind brain implants used to activate neural circuits responsible for vision, hearing or movement. ...

An achievement by UCLA neuroscientists could lead to a better understanding of astrocytes, a type of cell in the brain that is thought to play a role in Lou Gehrig's disease, also called amyotrophic lateral sclerosis, or ...

Time flows, time flies, time stands still. All these expressions show just how highly variable, depending on multiple factors, our perception of the passage of time can be. How is this subjective experience embodied in the ...

Duke University researchers have identified a common mechanism underlying separate forms of dystonia, a family of brain disorders that cause involuntary, debilitating and often painful movements, including twists and turns ...

A severely brain injured woman, who recovered the ability to communicate using her left eye, restored connections and function of the areas of her brain responsible for producing expressive language and responding to human ...

0 comments

Please sign in to add a comment.
Registration is free, and takes less than a minute.
Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.